I doubt you'll get much of a result by approaching the driver except maybe a grumbling (mayb a few norty words thrown at you too) But you should certainly give it a go. Failing that, contact the bus garage or operator or indeed TFL... if u get a nasty response from the bus driver make a point of getting his driver number - if he refuses make a note of the time and stop and if possible the number on the side of the bus. I once reported some norty behaviour of a community officer on a bus once to TFL and had a very speedy and positive response. Hope this helps.